This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The primary objective of this study is to establish the genetic basis for juvenile rheumatoid arthritis and juvenile spondyloarthropathy (JRA/JspA), the most common chronic arthropathies of childhood. The approach will use integrated genomics to identify 3 elements that are likely to have a genetic basis-susceptibility, clinical outcome, and responses to treatment.